Ferrari chairman Sergio Marchionne has called for a rethink over the idea of elimination qualifying in Formula 1, after saying that he isn't sure Ferrari can accept the proposed format.

F1 teams approved a plan last week to bring in a knockout format on Saturdays, in a bid to mix up grids and deliver a more exciting spectacle on race days.

However, just a few days after the announcement, the planned introduction at the Australian Grand Prix has had to be delayed because Bernie Ecclestone's FOM company cannot prepare timing software in time.

With the plans now on the back burner, Marchionne believes that the matter needs looking at again, as he suggest the Italian company is against any tweaks to the current qualifying format.

"I think we need more discussions about the new qualifying format," he told reporters during a media briefing at the Geneva motorshow.

"We must be careful not to upset the system. I'm not sure Ferrari can accept Bernie's ideas.

"We need to understand it better - and I don't think every team agrees with the proposal."

Mercedes worries

Marchionne said he was satisfied with the progress that Ferrari had made with its SF-16H, but was equally concerned that Mercedes had not yet shown its hand yet.

"The results that I saw at the first test in Barcelona are encouraging," he said. "Our car is good and competitive and our drivers are confident.

"But we've a lot of work to do to develop the car well for Melbourne."

And although Marchionne has previously declared that his only interest was in winning Melbourne, he has now admitted that the matter is not just down to his own team's performance.

"I hope we can see Ferrari on the front row from the first GP of the year," he said. "But we need to wait a bit of time.

"I don't trust in [the lap times shown by] Mercedes. When they are calm, it means we need to worry.

"The most important thing is that our car is extremely competitive. After that, we will see if we can win or not."